I planned to take my DC to the Tower of London tomorrow and decided to book online as there is a discount. I chose the option to collect the tickets on-site as otherwise you had to print them (says you can't show them on your phone). However, after buying them, it said I had to print the confirmation email and bring it along! Seems ridiculous as surely people who choose the option to collect on-site are those who can't print the tickets.
Anyway, I wondered if anyone had done similar and been able to get away with showing the confirmation on their phone? I would give them a call but we have to catch an early bus and they probably won't be open.